1. Field
This invention pertains to an apparatus and method for preventing, inhibiting progression of, and/or correcting plagiocephaly, an abnormal shape of the head of a human, usually an infant. The invention relates to a dynamic head support with sequential inflation and deflation of its compartments to provide variable external light pressures to the cranial vault and gentle changes in head position.
2. Description of the Related Art
The cranium, or skull, of a human infant is made up of several bone plates bridged by compliant membranous separations, known as sutures. These sutures solidify to herald the completion of rapid brain growth at eighteen to twenty-four months of age. Normally, the infant skull is symmetrical in shape. However, the shape of the head may be influenced by in utero constraint, external pressures during the birth process, as well as modeling and gravitation forces on the rapidly developing skull of an infant after birth. A condition known as occipital positional plagiocephaly, or deformational plagiocephaly, results in an asymmetrical head. This abnormal skull is most often a classic parallelogram or rhomboid shape, with bulging of the forehead and forward displacement of one ear as well as facial asymmetry, when observed from a top down or plan view.
Approximately one out of every three hundred healthy birth infants have a noticeable flattening of the head, asymmetry of the skull base and face, or both. Risk factors for plagiocephaly include prematurity, multiple births (twins, triplets), congenital anomalies, neurological injury, delayed muscle and motor development, tumors, and cervical defects.
Positional plagiocephaly has had an increased incidence since 1992 when the American Academy of Pediatrics initiated the “Back to Sleep” campaign, encouraging the placement of infants on their backs instead of their stomachs for sleeping purposes. The campaign reduced the occurrence of sudden infant death (SIDS), but led to a notable escalation in the number of plagiocephalic children. Another factor that may have contributed to the greater incidence of deformational plagiocephaly is increased usage of car seats, infant carriers, baby swings, “bouncy seats,” strollers, cribs and stationary toy gyms. Yet other factors may include feedings and social interactions that are routinely offered from the same side of the infant, as well as a preferred position when carrying the child.
Dysfunction of the neck musculature is almost universally associated with plagiocephaly. Neck abnormality, such as torticollis, is one important cause of plagiocephaly; likewise, existing skull deformity predisposes to torticollis and other forms of neck imbalance. Long term problems associated with plagiocephaly include subtle cerebral dysfunction (language disorders, learning disability, attention deficits and disorders of processing sensory stimulation), various functional disabilities caused by facial and jaw asymmetry, and psychosocial issues such as depression and tainted self-image.
Early assessment, diagnosis, and rehabilitation of plagiocephaly have been prerequisites for successful treatment to date. The value of education of caregivers, hospital personnel, and parents about the importance of alternating infant sleeping and feeding orientations should not be overlooked. Additionally, supervised “tummy time” for infants continues to be encouraged. Since 80% of postnatal brain growth, which can direct head shape, occurs early in life, plagiocephalic patients under the age of 18 months are also often given active and passive neck stretching exercises, to perform regularly, as the first line of treatment.
Helmet therapy, or use of external cranial remodeling orthotic devices, has been used alone and as an adjunct treatment option for plagiocephaly. These orthotic devices are predicated upon the theory that pressure from a rapidly growing brain against a concave surface will round flattened or deformed areas caused by earlier pressure against a flat surface. The optimum response for orthotic helmets, bands and caps is said to occur at ages of 4-12 months, which represents the period of greatest malleability of the skull bone, with the normalizing effect of rapid brain growth. Nonetheless, 25% of infants 3-6 months of age, 70% of infants 6-18 months of age, and 100% of older children undergo surgical correction for progression of the condition.
An orthotic helmet for treating deformational cranial asymmetry is shown in U.S. Pat. No. 4,776,324, granted to S. K. Clarren, on Oct. 11, 1988. The dimensions of the therapeutic helmet cavity are prescribed in relation to specific CT scan sections of the plagiocephalic infant's cranium, as shown in FIGS. 3 and 4 of the Clarren patent. A graded series of sized helmets is provided for such treatments. Each helmet cavity is configured to accommodate and treat infants of specified ages and degrees of plagiocephaly.
Orthotic bands, or caps, for remodeling the cranium are disclosed in U.S. Pat. No. 5,951,503, granted Sep. 14, 1999 to Jeanne K. Pomatto, and U.S. Pat. No. 6,423,019, granted Jul. 23, 2002, to Francis Papay et al. Each band provides at least one recess into which the skull may be remodeled as it grows. The orthotic band of Papay et al further includes at least one expandable bladder, on the inner wall of the band.
Other orthotic devices are disclosed in U.S. Pat. No. 5,094,229, granted Mar. 10, 1992, to Jeanne K. Pomatto et al, and U.S. Pat. No. 6,428,494, granted Aug. 6, 2002, to Stannon F. Schwenn et al.
Despite some advances in cranial remodeling, these prior art appliances are costly, uncomfortable and unsightly to wear and difficult to retain in position. Moreover, these devices require both complex measures to accommodate each individual patient as well as the intervention of skilled doctors, educators, and trained medical personnel.
The key to successful management of deformational plagiocephaly is prevention of its occurrence altogether. A number of devices have been used with the goal of preventing early skull deformation including contour pillows, foam pads with cut-outs of varying sizes, and static infant positioning devices. However, none of these devices present dynamic options that also alter orientation of the infant's head to reduce “side preference,” favored head orientation by the infant which fosters progressive neck imbalance and skull deformity. Furthermore, all of the known devices and techniques also necessitate the costly involvement of knowledgeable, skilled care providers and educators to achieve satisfactory results.
The requirement for a simple, yet effective, dynamic head support that prevents deformational plagiocephaly, while obviating the need for skilled care providers and frequent intervention, remains unfulfilled.